Head for folding machine



Nov. 19, 1957 H. A. MoNTAlNE 2,813,284

HEAD FOR FOLDING MACHINE /ls 8 se s2 INVENTOR. HERBERT A. MONTAINEATTORNEY.

N0V 19, 1957 H. A.V MONTAINE HEAD FOR FOLDING MACHINE 2 Sheets-Sheet 2Filed May 28, 1957 INVENTOR. HERBERT Af. MONTAINE W f @Aw ATTORNEY.

United States Patent @ffice 2,813,284 Patented Nov. i9, 1957 HEAD FORFOLDING MACHINE Herbert A. Montaine, Lynn, Mass. Application May 28,1957, Serial No. 662,l68

13` Claims. (Cl. 12--55) This invention relates to rotary folding andpressing machines for folding a cemented or coated binding around theedges of upper stock to which it has been previously stitched and thenpressing the binding firmly against the opposite side of the stock tocause the binding to adhere to the stock. More particularly, theinvention relates to an improved rotary head for a folding machine ofthe type described in the patent to Andrew R. Ridderstrom, No.1,925,205, dated September 5, 1933.

The Ridderstrom machine, which is still in general use, employs as afolding instrumentality a rotary head provided with twenty-twoperipheral roller disks rotatable in operation in a direction oppositeto that of the head itself. The roller disks are mounted on individualshafts journalled within the head, on the other end of which individualgears are secured positively to rotate the disks. The rotary head ismounted diagonally with reference to the direction of the material feedand cooperation with a lower ridged feed roll, a stationary guide, and aheated retainer foot to effect a turning of the binding over the edge ofthe stock. The roller disks are mounted in the rotary head at an angleto the axis of rotation of the head and thus in cooperation with thelower feed roll function to feed the stock and bin-ding through themachine, Each of the roller disks is provided with a notch and camsurface on its periphery, these notches being so disposed that the rateof rotation imparted to the disks is such that as each disk reaches aposition directly over the lower feed roll, the notch therein is at thelower side of the disk and directly over the ridge on the feed roll. Thedisks, as the notches therein pass over the ridge on the roller, pullthe binding taut away from the stitch line, and then the cam surface issaid to provide positive rolling down of the binding edge.

ln spite of many disadvantages of the rotary head of the Ridderstrommachine, it has been in widespread continuous use since its introductionin the early 1920s. The obvious disadvantage of this head is itscomplexity; it includes twenty-two shafts disposed at an angle in thehead, twenty-two close tolerance gears secured to the shafts, andtwenty-two roller disks. The notches and cams on the roller disks mustbe machined after the head is assembled in order to achieve propertiming, and consequently cannot be heat treated to harden them.Consequently, the disks tend to wear out rapidly and experience hasshown that when the disks and gears become worn the entire head must bescrapped. Should the head be disassembled for any reason, it is usuallynecessary to employ a skilled mechanic to adjust the timing of the gearsand cams.` In addition to disk wear, the gears and shafts also wear outrather quickly; as would be expected for a mechanism of this complexity,it is designed to `be oiled, but since thevoil is prone to leak outaround the several shafts and onto the shoe stock being worked upon, themachine operators (who must pay for the material they damage) arecareful not to oil the head. The consequences are obvious.

The basic Ridderstrom machine was designed for fold- 2. ing and layingcemented tape, but has not been altered since the advent of coatedbinding which must be heated to liquefy the coating preparatory tosealing it against the upper stock. In the folding and rolling process,excess liquefied coating material is squeezed out from under thebinding, is sucked into the shaft journals and into the gears, andl uponcooling solidities and gums up the gears thereby causing a requirementfor increased driving power. Moreover, the coating material oftencontains tine abrasive particles which settle in the gear teeth tocontribute to rapid wear.

Apart from mechanical deficiencies of the type enu merated, the headalso has some functional disadvantages. The timing of the disks with therotation of the head is such that when all parts are perfect each rollerengages the` material before the previous one has left which is claimedto permit the following of abrupt turns in the folded edge. Applicanthas found, however, that with a difference in clearance between thelower feed roll and the disks of .005 from one disk to another (adifticult tolerance to maintain in a structure of this complexity)uneven pulling of the binding results, and frequently on abrupt turnsthe difference in the degree of contact between successive disks mayresult in one disk losing adequate contact with the work before the nextdisk engages the work causing unevenness in the laying of the tapeand/or throwing of the work from the machine.

Finally, the prior art rotary head does not pull the binding as tightlyagainst the stitching as is desired (a very thin French cord with thestitching exposed is the goal) because of the nature of the folding andlaying action of the machine. The guide and the presser foot initiatethe folding over of the binding, but the only pulling of the bindingaway from the stitching is performed by the notches in the disks whichpress or crush together the binding and leather over the ridge on thefeed roll. Thus, the binding is sealed to the leather at a point justforward of the rib on the feed roller as the notch goes by, andthereafter the cam surface of the disk simply rolls over the remainingwidth of the binding, the latter action in no way contributing tofurther pulling of the binding away from the stitch line. As a result,the binding is not as tightly pulled as would be preferred, a ridge orroll is formed in the binding at the fold line, and should there bevariations in the degree of contact between the feed roll and successivedisks (particularly in the notches), the pulling will be uneven and anunsatisfactory French cord will result.

With an appreciation of the enumerated disadvantages and shortcomings ofthe rotary head of the Ridderstrom machine, applicant has as a generalobject of the present invention to provide a rotary head -for themachine which overcomes these disadvantages.

Another object of the invention is to provide a rotary head for a rotaryfolding machine which is simple and inexpensive to construct.

Still another object of applicants invention is to provide a rotary headfor a rotary folding machine which has no moving parts and hence is notsubject to wear as on existing rotary heads.

Another important object of the invention is to provide a rotary headcapable of folding and laying a tighter binding than is possible withexisting rotary heads.

Another object of the invention is to provide a rotary head possessingthe foregoing advantages which can be directly substituted for therotary head of the Ridderstrom machine to permit the continued use ofthe many machines of this type which are now in service.

The machine on which the rotary head is intended for use is the same asthat shown in the Ridderstrom patent to which reference may be had fordetailed information concerning the points discussed above and for adetailed description of the construction and operation of the othermechanisms of the machine. The improvement forming the subject matter ofthe present application has to do with a rotary head which cooperateswith other parts of the machinegi. e., feed roll, guide and retainerfoot, in a manner similar to the rotary head of the Ridderstrom machineto fold and 'lay a binding tape in an improved manner.

ln accordance with the invention, the rotary head comprises a relativelythin circular disk mounted on a shaft to be driven in rotation, the headbeing mounted diagonally with reference to the direction of the materialfeed. About the outer periphery of the disk are formed va plurality ofridges and grooves disposed at a small angle to the plane of the disk,which in cooperation with the lower feed rol-l, functions to feed thework through the machine. With the binding spread from the leather stockby the guide, and through the cooperation of the retainer foot and thelower feed roll, the binding is held taut when presented to the ridgeson the rotary head. The ridges act to grasp the binding, pulling it tautover the edges of the stock and away from the stitching and pressing thebinding down smoothly and evenly with a continuing pulling and wipingaction, the effect of which extends across the entire width of thebinding. Successive ridges on the disk overlap each other, going aroundthe periphery, whereby the work is at all times held down positively byone ridge engaging the material to a considerable extent before the nextprevious ridge has left it. Each of the ridges is formed with a step atthe extremity thereof which first engages the work to afford positivegripping of the material and permitting the binding of leather ofabruptly varying thickness; e. g., from a single thickness of leather todouble thickness and back to single, without faltering. The provision ofthe step also afford a point on the forward extremity of each ridgewhich first engages the Work at a position near the front face of thedisk, such that when the disk is properly oriented with respect to thefeed rol-l, the feeding and pulling of the material are focussed atsubstantially the same point to permit following of abrupt turns withoutloss of firm pulling contact with the binding.

Other objects, features and advantages of the invention will becomeapparent, and its construction and operation better understood from thefollowing detailed description taken in connection with the accompanyingdrawings, in which:

Fig. 1 is a side elevation with portions broken away and in Verticalsection of the machine embodying the invention;

Fig. 2 is a sectional view of the improved rotary head of the inventionand the mounting thereof;

Fig. 3 is a fragmentary side elevation of the rotary head of theinvention;

Fig. 4 is a fragmentary end view of the rotary head;

Fig. 5 is a View illustrating the rotary head and the positioningthereof relative to the work support roll;

Fig. 6 is a fragmentary view illustrating the operation ,of the improvedrotary head; and

Fig. 7 is a fragmentary plan view further illustrating the operation ofthe invention.

Referring now to the drawings, and in particular to Figs. 1 and 6, themachine on which the invention is embodied comprises a suitable base lilto which is hinged an upper supporting frame l2 which provides a housingfor some of the moving parts of the machine. An overhanging arm 14extends forwardly from frame 12 and is provided with an oblique bore inwhich a rotatable shaft 16 is journalled. Secured to the rear end ofshaft i6 is a spiral gear 18 meshing with a spiral worm gear Ztl whichis carried at the forward end of driving shaft 22 which is suitablyjournalled in the walls of frame l2. This shaft may be driven by meansof a suitable belt pulley (not shown) through a suitable clutchmechanism.

Also journalled in frame 12 is a shaft 24 carrying a worm gear 26operated from shaft 22 by a worm shaft 28. To the forward end of shaft24 is connected a shaft Si) on which is mounted a Work supporting roll32 carried by a support 34. The roll 32 is thus driven in the directionindicated during the feeding and.` folding operations. The forward endof roll 32 may be smooth or knurled steel, or provided with a rubberring, and has a peripheral guide rib 36. rlhe support 34 carries a guide38 secured thereto by means of a screw 40, the guide having anupstanding wall 42 adapted to initially position the binding strip whenthe stock is placed in the machine for the folding operation.

Extending through the front wall of the housing 14 is a shaft 43 whichcarries a bracket 44, which in turn, at the outer end thereof, carriesan inclined guide 46, which may be termed the retainer support. Aretainer shaft or spindle 4S is slidingly mounted within guide 46, andis urged downwardly by a compression spring engaging a plate 52 securedto the upper end of the spindle. The compression of spring 50 may beadjusted by nut dita threaded to the upper end of lstud 5017, the otherend of which is anchored in bracket 44. Plate 52 slides freely on stud561; and is further guided by pin 51, also anchored in bracket 44. Thelower end of spindle 48 is bi-furcated to provide inner and outer forks54 and 56 between which a retainer foot roll or disk 58 is rotatablymounted on a suitable shaft. This retainer foot roll is positioneddirectly above and at an angle to the projecting guide rib 36 on thelower work supporting roll 32, and cooperates therewith to maintain thestitch line on the rib. Retainer guide 46 is provided with a heatingelement (not shown) which is connected in circuit by means of cable 59which may be connected to a suitable source of power. The heatingelement heats the guide 46 and the spindle 48, this heat being conductedto the lower end thereof to heat the forks 54 and 56 to the requiredtemperature to liquefy the cement or gum coating on the binding tape.The coated side of the tape confacts the inner fork 56 whereby thecoating is continuously and constantly heated to liquefaction before thetape is folded and pressed down upon the leather.

The machine thus far described corresponds generaliy with theRidderstrom machine, and no alteration or modi cation is necessary toutilize applicants novel rotary head in place of the complex head of theprior art ma chine. Referring to Figs. 1 and 2, the rotary head inaccordance with the present invention comprises a shaft 16 to the rearend of which is secured Worm gear i8, and to the front end of which issecured a circular disk 6l) having a plurality of ridges and grooves onits periphery, the nature of which will presently be described indetail. The shaft is journalled in a bushing 6?, carried in the obliquebore of overhanging arm i4 and secured against rotation by retainingmeans in tic arm (not shown) cooperating with the bushing. Bushing e2 ispreferably provided with a liner 64, of bearing material to prolong itslife, and has an opening for the ap.- plication of oil. To providerigidity and strength to disk 60, and to permit exchange of the diskswhen worn, a substantially frustro-conical member 63 is secured to shaft16, as by a key 7), the disk 60 being driven thereby through a pin 72which engages member 68 and the disk. Disk is maintained in contact withmember 63 by a screw 74 threaded into `the end of shaft 16, and shaft lois retained in the bushing 62 by a retainer ring 76 secured to shaft 16,or by setscrews '7S and Stb, washer S2 formed of fiber or the likepreferably being provide-:l as a thrust bearing between the bushing andretainer ring. The assembly just described is positioned in the arm 14such that the disk 60 is located directly over the roller 32, but at anangle thereto and to the direction of feed movement, More specifically,as shown in Fig.

as rae s4 di'sk 60` isvv mounted directlly` above roller @outwardly ofguide rib 36, with the disk 60 substantially contacting the rib 36 andthe midpoint' of that portion` of roller 32 which is forward of the rib.As shown in Fig'. l, the point of cooperation of the disk 60 and roller32 is behind the guide and retainer foot.

Referring now to` Figs. 3, 4 and 5, the disk 60 is formed of steel orsimilar hard material about 1A: inchthick, the rear face being hat torest firmly against member 68. The front face of the disk is taperedslightly from the periphery toward the center, a taper of having beenfound satisfactory. The disk is of slightly larger diameter than member68, the rear portion, however, being machined to substantially thediameter of member 68, leaving, in effect, a rim about %4 inch wide andof slightly larger diameter. The rim is provided around its peripherywith a plurality of spaced grooves 66a, each inclined at equal smallangles to the plane of disk 60, to provide a series of ridges 60]; andgrooves 60a, each eX- tending around a portion of the periphery of thedisk. In a preferred embodiment, disk 60 at the rim is about 23/16inches in diameter with-twenty-two equally spaced grooves having a widthof about .020 inch' cut therein to a depth of about .040 inch, eachinclined at anl angle of about 7 degrees to the plane of the disk. Afthe intersection of cach groove with the front surface of the` disk, theforward extremity of each ridge is rounded at 60e (as best seen in Fig.4), and the disk face cut away slightly between adjacent groove termini,as shown at 60d. As best seen in Fig. 5, this construction provides asuccession of ridges, each overlapping more that half of the next, andeach having in the nature of an inclined step at 60C, which by virtue ofthe tapered front face of the disk, is the most forward point on thedisk. Thus, with rotation of the rotary head in the direction indicated,the point 60e of each ridge is the first to engage the Work material,and the engagement of successive ridges with the material causes a feedof the material in a manner generally similar to that of a screw. Theoverlapping of successive ridges to the extent provided insuresengagement of at least one ridge with the material at all times, and fora large percentage of the time, two ridges engage the material. Theinclined steps 60k, on the other hand, permit the abrupt turning of thematerial (about point 69C) without loss of engagement of the ridges withthe material.

As mentioned in connection with Fig. l, and also shown in Figs. 5 and 6,the rotatable headl is mounted on an axis extending at an angle to thedirection of feed; i. e., the path of the rim of disk 60 is at an anglewith the axis of rotation of feed roller 32. Means is provided foryieldingly pressing the feed roller upward, and the rotary head ispositioned directly above the feedroller such that the outer peripheryof disk 60 is tangent to two points on the feed roller, at point 36' onthe periphery of guide rib 36, and at point 32' substantially midwaybetween the guide rib and the forward end of the feed roll.

Fig. 6 illustrates the application of the machine to the folding of anedge of stock, such as a piece of leather Sil having stitched along itsedge at 32 a binding strip 8d, usually of fabric material. In commercialpractice, the binding strip is coated along the inner face at S6 withcement or gum. In turning French cord', as illustrated in the presentcase, the stock is placed in the machine so that the guide rib 36 wi-llproject into the stitch line 82, and as the stock is fed through themachine this guide rib follows the stitch line and' guides the stock,the retainer foot roll 58 traveling along the edge of the material Si)and above rib 36 so as to hold the stock on the guide rib. The bindingis tirst spread out and pressed away fromtthe stock at the stitch lineby the action of the rib' on feed roll 32,` and the upstanding wall 42of the guide 33 guides the binding into contact with the heatedl fork 58of the retainer toot so 6 as to heat the cement or gum coating toliqueii'cation before the binding is folded and pressedY down upon theleather.

The stock is simultaneously fed on and over the feed roll 32 by meansofthe ridges 60b on the periphery of the rotary head. The head isarranged torotate through a path directly behind the retainer foot andguide 42, the ridges being a-t an angle to the direction of feed'. Thehead is driven in the direction indicated, each of inclined steps 60Cengaging the binding as it passes in proximity to guide rib 36 (i. e.,approximately at point 36') and drawing it tightly against rib 36 whichengages the stitch line 82'. Upon further rotation of the head, theridges successively engage the binding` and by a wiping action obliquelyacross the' binding continueto draw it against the guide rib and pressit against the leather. It is thus to' be noted that each ridge 60hengages the binding from initial engagement at point: 36' until itrotates past point 32', exerting a` continuing drawing and pressingaction throughout the period of enjoyment whcreby a very tightly drawn'cord (sufficiently tight to expose the stitch line on the underside ofstock 3G) may be realized. It is to be noted also that the folding andpressing are both accomplished in' the regio-n between points 3'6' and32', spaced apart of the order of 3/16 inch, but by reason of theinclined .steps 50c at the forwardmost point on the disk, thesubstantial overlap of successive ridges, and the thinness of the ridgedrim, it is possible to make close or abrupt turns in the folded edge andstill' preserve an even and uniform fold, which is still further insuredby the fact that the feed is continuous and steady- Well before thematerial is released by one of the ridges, it is engaged by the nextsucceeding one without the' intermittent release which often occurs withthe roller disks of the Ridderstrom head, especiallyl when they becomeslightly worn.

The' present head construction, again by reason of the steps 60C and thesubstantial overlap of successive ridges, insures' the layingV of aneven and uniform binding on stock of varying texture and thickness. Forexample, the base' material may change abruptly from single to doublethickness and back to single;` the inclined steps 60C, and thecontinuous drawing action of the ridges prevent hesitation or falteringof the feed when the double thickness is encountered, thus insuring aneven and uniform fold. Similarly, the present construction affords theuniform and unfaltering feed of smoothstock, such as patent leather, amaterial difficult to work on with the Ridderstrom head.

It has been observed that excess gum pressed out from under the foldedbinding does not collect to any extent in the grooves 60a, but insteadcollects harmlessly immediately behind the rim, and then withoutappreciable accumulation by reason of the fact that the surface issmooth. Should the gum accumulate' in the grooves, it may be readily`and quickly'A removed by application of a wire brush while the head isrotating.

Froin the foregoing description, a number of advantages of applicantsrotary h'e'ad over the Ridderstrom head will be readily apparent. Apartfrom the shaft on which it rotates, the head has no moving parts to wearout, and the shaft may be oiled without fear ofI leakage to the work.The head is quieter' in operation than the prior art head and remainsclean over extended periods of use. It can be manufactured ata fractionof the cost of the previous" head, and when it becomes worn, the disk 60can be replaced simply by removal of screw 74, with the remainder ofthehead on the machine 'and Without disturbing the setting` of the headrelative tothe feed roll. There are no timing problems with the presenthead, and maintenance can be done by the machine operator. Mostimportant, the construction' of the disk insures `constant engagementwith the work` material;` and continuingl pulling of the binding`against the stitch 'line' to produce a tighter, smooth"N er,` and-moreuniform binding than is possible with folding machines: now inexistence.

While in the description of the invention certain dimensions and angleshave been mentioned, it will be understood that the invention is notlimited thereto, but are merely by way of example. Applicant is awarealso that the invention may be embodied in other specific forms withoutdeparting from the spirit thereof, and therefore desires that thedisclosed embodiment be considered illustrative, reference being had tothe appended claims to indicate the scope of the invention.

What is claimed is:

l. In a rotary folding machine, a rotatable head comprising a circulardisk having a plurality of grooves distributed around its periphery andinclined at a small angle to the plane of said disk and forming a likeplurality of similarly inclined ridges each 4overlapping a substantialportion of adjacent ridges.

2. In a rotary folding machine, a rotatable head comprising a thincircular disk having a plurality of grooves on its periphery inclined ata small angle to the plane of said disk and terminating at oppositefaces of said disk t form a like plurality of similarly inclined ridgeseach overlapping a substantial portion of adjacent ridges.

3. ln a rotary folding machine, a rotatable head comprising a thincircular disk having front and back surfaces the front surface of whichhas a small taper from the periphery toward the center, said disk havinga plurality of narrow grooves `on its periphery inclined at a smallangle to the plane of said disk and terminating at the front and backsurfaces of said disk and forming a like plurality of similarly inclinednarrow ridges each overlapping a substantial portion of adjacent ridges,each of said ridges at the front face termination thereof being formedwith a step.

4. In a rotary folding machine, a rotatable head comprising, a shaftadapted to be driven at one end thereof, a generally cylindrical membersecured to the other end of said shaft and having an end face normal tothe axis of said shaft, and a thin circular disk having a slightlylarger diameter than said member removably secured to the end face ofsaid member, said disk having a plurality of narrow grooves on itsperiphery inclined at a small angle to the plane of said disk andterminating at the surfaces of said disk and forming a like plurality ofsimilarly inclined ridges each overlapping a substantial portion ofadjacent ridges, each of said ridges at the termination thereof with thesurfaces of the disk opposite sai-d member being formed with a stepinclined `at an angle to a radius of said disk drawn to the saidtermination.

5. ln a rotary folding machine, a rotatable head cornprising, a shaftadapted to be driven in rotation from one end thereof, a substantiallyfrustro-conical member secured to the other end of said shaft and havingan end ace normal to the axis of said shaft, and a thin circular disk,having front yand back surfaces, removably secured to said member withthe back surface in engagement with said end face, the front surface ofsaid disk having a slight concave taper from the periphery toward thecenter, said disk having a plurality of narrow grooves on its peripheryinclined at a small angle to the plane of said disk intersecting thefront and back surfaces of said disk and forming a like plurality ofsimilarly inclined ridges each overlapping a substantial portion of thelength of adjacent ridges, each of said ridges at the intersectionthereof with the front surface of said ldisk being formed with a stepinclined at an angle to a radius of said disk drawn to saidintersection.

6. In a rotary folding machine of the type having a driven feed rollprovided with a guide rib, a rotatable feeding and pressing headcomprising a circular disk disposed at an angle to said feed roll andtangentially approaching said feed roll at said guide rib and at a pointforward of said rib, said disk having a plurality of narrow grooves onits periphery inclined at a small angle to the plane of said disk andterminating at the opposite faces of said disk and forming a likeplurality of similarly inclined ridges each overlapping a substantialportion of adjacent ridges.

7. In a rotary folding machine of the type having a feed roll drivenabout a horizontal axis and provided with ya peripheral guide rib, and aretainer roller disposed above said guide rib, the combination of arotatable disk inclined at an angle to said feed roll and tangentiallyapproaching said feed roll at said guide rib `and at a point forward ofsaid rib, said disk having a plurality of narrow grooves distributedabout its periphery inclined at a small angle to the plane `of said diskand terminating at the opposite faces of said disk and forming a likepluraltiy of inclined ridges each overlapping a substantial portion ofadjacent ridges and continuously engaging the work during rotationbetween said rib and said point.

8. In a rotary folding machine of the type having a driven feed rollprovided with a guide rib spaced from the forward end thereof and aretainer roller disposed above said guide rib, the combination of arotatable head including a shaft adapted to be driven in rotation fromone end thereof, a substantially frustro-conical member secured to theother end of said shaft and having an end face normal to the axis ofsaid shaft, and a thin circular disk, having front and back surfaces,removably secured to said member with its back surface in engagementwith said end face, the front surface of said disk being taperedinwardly slightly from the periphery toward the center, said disk havinga plurality of grooves on its periphery inclined at a small angle to theplane of said disk intersecting the front and back surfaces of said diskand forming a like plurality of similarly inclined narrow ridges eachoverlapping a substantial portion of the length of adjacent ridges, saiddisk being inclined at an angle to said feed roll and tangentiallyapproaching said feed roll at said guide rib and at a point forward ofsaid rib, each of said ridges on said disk being of a length greaterthan the distance between said rib and said point and with the aforesaidoverlapping of ridges continuously engage the work during rotationbetween said rib and said point.

9. Apparatus in accordance with claim 8 wherein each of said ridges atthe intersection thereof with the front surface of said disk is formedwith a step inclined at an angle to a radius drawn to the point ofintersection to provide a point about which the work may be turned andto improve engagement of the disk with work of varying thickness.

l0. In a machine for folding and laying a binding strip stitched to aface of a sheet of material along an edge thereof of the type having afeed roll for feeding the sheet and strip and provided with a guide ribfor engaging the said face of the material and the strip at the stitchline to spread the strip away from the material at the stitch line andto guide the material, and a retainer roller for yieldingly pressing thematerial against the feed roll in the vicinity of said guide rib, thecombination of a thin, peripherally ridged disk inclined at an angle tosaid feed roll and tangentially approaching said feed roll at said guiderib and at a point forward of said guide rib for folding the strip anddrawing it away from said stitch line to lay it upon the other face ofthe material and press it thereagainst.

ll. in a machine for folding and laying a binding strip stitched to aface of a sheet of material along an edge thereof of the type having afeed roll for feeding the sheet and strip and provided with a guide ribfor engaging the said face of the material and the strip at the stitchline to spread the strip away from the material at the stitch line andto guide the material, and a retainer roller for yieldingly pressing thematerial against the feed roll in the vicinity of the guide rib, thecombination of a thin disk inclined at an angle to said feed roll anddriven in rotation in a direction opposite to the said feed roll, saiddisk having a plurality of narrow ridges on its periphery inclined at asmall angle to the plane of said disk intersecting opposite surfaces ofthe disk each overlapping a substantial portion of adjacent ridges, theperiphery of said disk tangentially approaching said #feed roll at saidguide rib and at a point forward of said guide rib for folding saidstrip and continuously drawing it away from said stitch line to lay itupon the other face of the material and press it thereagainst.

l2. In a folding machine for folding a binding strip ystitched adjacentthe edge of a sheet of material of the type including a driven feed rollprovided with a guide rib for engaging the material at the stitch line,and a roll at said guide rib and at a point forward of said guide riband provided on its periphery with a plurality of overlapping narrowridges inclined at a small angle to the plane of said disk adapted tocontinuously engage said strip while rotating between said guide rib andsaid point to fold said strip and draw it away from said stitch line tolay it upon the other face of the material and press it thereagainst.

13. Apparatus in accordance with claim 12 wherein each of said ridges isformed at the extremity thereof which first engages the material with aninclined step to provide a turning point for the material and topositively feed material of varying thickness.

No references cited.

